Drawing apparatus



Aug. a, 1926.4

A 1,594,822 '.W. E. ELAM nnAwIrAa APPARATUS Filed August 13. 1923 Patented Aug. 3, 1926.

UNITED STATES PATENT OFFICE.

DRAWING- APPARATUS.

Application filed August 13, 1923. Serial No. 656,993.

An object of this invention is to provide means whereby a triangle or analogous member to serve as a guide for a pencil or other marking implement may normally slide freely over the surface upon which marks are to be made, but which when pressure is applied to certain portions of its upper surface be comes non-slipping so long,` only as pressure continues on those portions.

In the accompanying drawings F l shows in plan View, a triangle provided with one form of my device,

Fig. 2 is a section on the line 2 2, Fig. l,

Fig. 8 is a section similar to Fig. 2 showing a. modified triangle.

In these views, Gr represents the body of a triangle or light plate.

In Figures l and 2 a resilient non-slipping member M normally lies Wholly between the faces of the plate Gr and may be sprung downward into contact with the paper.

In Figure 8 thin strata of the plate have been removed over a suitable area as shown at N', N2 leaving an integral thinner resilient portion 0 between, and normally spaced from, each of the plate faces. This thin part is resilient and its central portion may be n'essed down upon the paper. In each form the lower face is preferably roughened e. g. by means of sand P, Fig. 3.

The plate may now be moved freely over the paper to exact position, and when so adjusted slight pressure of the lingers on the depressiblc area causes non-slipping engagement with the paper, but only as long as pressure continues. This normal easy slipping` is highly important under various conditions, e. g'. when two plates, or triangles, are in marginal contact and are to be slipped alternately.

lllhat l claim is l. A draftsmans plane marking guide plate having anV integral thinner resilient portion between and normally spaced from each of the plate faces andadapted for non-slipping engagement with the drawing surface while pressed against that surface.

2. In apparatus of the class described. a guide plate adapted to rest upon a surface upon which a line is to be drawn and provided with a ythinner resilient non-slipping portion secured to the plate at the margins of said non-slipping portion and normally lying wholly between the faces of said plate.

In testimony whereof I hereunto aiiiX my signature.

W. E. ELAM. 

